/*****************************************************************************/
/*                                                                           */
/*                                segments.c                                 */
/*                                                                           */
/*                   Lightweight segment management stuff                    */
/*                                                                           */
/*                                                                           */
/*                                                                           */
/* (C) 2001-2009, Ullrich von Bassewitz                                      */
/*                Roemerstrasse 52                                           */
/*                D-70794 Filderstadt                                        */
/* EMail:         uz@cc65.org                                                */
/*                                                                           */
/*                                                                           */
/* This software is provided 'as-is', without any expressed or implied       */
/* warranty.  In no event will the authors be held liable for any damages    */
/* arising from the use of this software.                                    */
/*                                                                           */
/* Permission is granted to anyone to use this software for any purpose,     */
/* including commercial applications, and to alter it and redistribute it    */
/* freely, subject to the following restrictions:                            */
/*                                                                           */
/* 1. The origin of this software must not be misrepresented; you must not   */
/*    claim that you wrote the original software. If you use this software   */
/*    in a product, an acknowledgment in the product documentation would be  */
/*    appreciated but is not required.                                       */
/* 2. Altered source versions must be plainly marked as such, and must not   */
/*    be misrepresented as being the original software.                      */
/* 3. This notice may not be removed or altered from any source              */
/*    distribution.                                                          */
/*                                                                           */
/*****************************************************************************/

#include <stdarg.h>
#include <string.h>

/* common */
#include "chartype.h"
#include "check.h"
#include "coll.h"
#include "scanner.h"
#include "segnames.h"
#include "strstack.h"
#include "xmalloc.h"

/* cc65 */
#include "codeent.h"
#include "codeseg.h"
#include "dataseg.h"
#include "error.h"
#include "textseg.h"
#include "segments.h"

/*****************************************************************************/
/*                                   Data                                    */
/*****************************************************************************/

/* Pointer to the current segment list. Output goes here. */
Segments *CS = 0;

/* Pointer to the global segment list */
Segments *GS = 0;

/* Actual names for the segments */
static StrStack SegmentNames[SEG_COUNT];

/* We're using a collection for the stack instead of a linked list. Since
** functions may not be nested (at least in the current implementation), the
** maximum stack depth is 2, so there is not really a need for a better
** implementation.
*/
static Collection SegmentStack = STATIC_COLLECTION_INITIALIZER;

/*****************************************************************************/
/*                                   Code                                    */
/*****************************************************************************/

void InitSegNames(void)
/* Initialize the segment names */
{
  SS_Push(&SegmentNames[SEG_BSS], SEGNAME_BSS);
  SS_Push(&SegmentNames[SEG_CODE], SEGNAME_CODE);
  SS_Push(&SegmentNames[SEG_DATA], SEGNAME_DATA);
  SS_Push(&SegmentNames[SEG_RODATA], SEGNAME_RODATA);
}

void SetSegName(segment_t Seg, const char *Name)
/* Set a new name for a segment */
{
  SS_Set(&SegmentNames[Seg], Name);
}

void PushSegName(segment_t Seg, const char *Name)
/* Push the current segment name and set a new name for a segment */
{
  if (SS_IsFull(&SegmentNames[Seg])) {
    Error("Segment name stack overflow");
  } else {
    SS_Push(&SegmentNames[Seg], Name);
  }
}

void PopSegName(segment_t Seg)
/* Restore a segment name from the segment name stack */
{
  if (SS_GetCount(&SegmentNames[Seg]) < 2) {
    Error("Segment name stack is empty");
  } else {
    SS_Drop(&SegmentNames[Seg]);
  }
}

const char *GetSegName(segment_t Seg)
/* Get the name of the given segment */
{
  return SS_Get(&SegmentNames[Seg]);
}

static Segments *NewSegments(SymEntry *Func)
/* Initialize a Segments structure (set all fields to NULL) */
{
  /* Allocate memory */
  Segments *S = xmalloc(sizeof(Segments));

  /* Initialize the fields */
  S->Text = NewTextSeg(Func);
  S->Code = NewCodeSeg(GetSegName(SEG_CODE), Func);
  S->Data = NewDataSeg(GetSegName(SEG_DATA), Func);
  S->ROData = NewDataSeg(GetSegName(SEG_RODATA), Func);
  S->BSS = NewDataSeg(GetSegName(SEG_BSS), Func);
  S->CurDSeg = SEG_DATA;

  /* Return the new struct */
  return S;
}

Segments *PushSegments(SymEntry *Func)
/* Make the new segment list current but remember the old one */
{
  /* Push the current pointer onto the stack */
  CollAppend(&SegmentStack, CS);

  /* Create a new Segments structure */
  CS = NewSegments(Func);

  /* Return the new struct */
  return CS;
}

void PopSegments(void)
/* Pop the old segment list (make it current) */
{
  /* Must have something on the stack */
  PRECONDITION(CollCount(&SegmentStack) > 0);

  /* Pop the last segment and set it as current */
  CS = CollPop(&SegmentStack);
}

void CreateGlobalSegments(void)
/* Create the global segments and remember them in GS */
{
  GS = PushSegments(0);
}

void UseDataSeg(segment_t DSeg)
/* For the current segment list, use the data segment DSeg */
{
  /* Check the input */
  PRECONDITION(CS && DSeg != SEG_CODE);

  /* Set the new segment to use */
  CS->CurDSeg = DSeg;
}

struct DataSeg *GetDataSeg(void)
/* Return the current data segment */
{
  PRECONDITION(CS != 0);
  switch (CS->CurDSeg) {
  case SEG_BSS:
    return CS->BSS;
  case SEG_DATA:
    return CS->Data;
  case SEG_RODATA:
    return CS->ROData;
  default:
    FAIL("Invalid data segment");
    return 0;
  }
}

void AddTextLine(const char *Format, ...)
/* Add a line of code to the current text segment */
{
  va_list ap;
  va_start(ap, Format);
  CHECK(CS != 0);
  TS_AddVLine(CS->Text, Format, ap);
  va_end(ap);
}

unsigned AddCodeLine_LastLineNum = 0;
char AddCodeLine_Buf[4096];
char AddCodeLine_Fun[128];
void AddCodeLine_(const char *Format, ...)
/* Add a line of code to the current code segment */
{
  va_list ap;
  va_start(ap, Format);
  CHECK(CS != 0);
  CS_AddVLine(CS->Code, CurTok.LI, Format, ap);
  va_end(ap);
}

void AddCode(opc_t OPC, am_t AM, const char *Arg, struct CodeLabel *JumpTo)
/* Add a code entry to the current code segment */
{
  CHECK(CS != 0);
  CS_AddEntry(CS->Code, NewCodeEntry(OPC, AM, Arg, JumpTo, CurTok.LI));
}

void AddDataLine(const char *Format, ...)
/* Add a line of data to the current data segment */
{
  va_list ap;
  va_start(ap, Format);
  CHECK(CS != 0);
  DS_AddVLine(GetDataSeg(), Format, ap);
  va_end(ap);
}

int HaveGlobalCode(void)
/* Return true if the global code segment contains entries (which is an error) */
{
  return (CS_GetEntryCount(GS->Code) > 0);
}

void RemoveGlobalCode(void)
/* Remove all code from the global code segment. Used for error recovery. */
{
  CS_DelEntries(GS->Code, 0, CS_GetEntryCount(GS->Code));
}

void OutputSegments(const Segments *S)
/* Output the given segments to the output file */
{
  /* Output the function prologue if the segments came from a function */
  CS_OutputPrologue(S->Code);

  /* Output the text segment */
  //  TS_Output(S->Text);

  /* Output the three data segments */
  DS_Output(S->Data);
  DS_Output(S->ROData);
  DS_Output(S->BSS);

  /* Output the code segment */
  CS_Output(S->Code);

  /* Output the code segment epiloque */
  CS_OutputEpilogue(S->Code);
}
